1. Field of the Invention
Exemplary aspects of the present invention generally relate to an image forming apparatus, and more particularly to an image forming apparatus including a recording head that ejects liquid droplets vertically upward.
2. Description of the Related Art
One example of related-art image forming apparatuses such as printers, copiers, plotters, facsimile machines, and multifunction devices having two or more of printing, copying, plotting, and facsimile capabilities is an inkjet recording device employing a liquid ejection recording method. The inkjet recording device includes a recording head that ejects droplets of a recording liquid such as ink from nozzles in the recording head onto a sheet of recording media while the sheet is conveyed to form an image on the sheet. Examples of an inkjet recording device include a serial-type image forming apparatus, in which the recording head ejects ink droplets while moving in a main scanning direction to form an image on the sheet as the sheet is moved in a sub-scanning direction perpendicular to the main scanning direction, and a line-type image forming apparatus equipped with a line-type recording head that ejects ink droplets and does so without moving to form an image on the sheet as the sheet is moved in the sub-scanning direction.
The recording head typically ejects ink droplets vertically downward onto a sheet conveyed past the recording head so that an image is formed on an upward facing side of the sheet. The inkjet recording device further includes a servicing mechanism to maintain stable ejection of ink droplets from the nozzles in the recording head (i.e., to keep the nozzles clean). The servicing mechanism includes a cap that covers a nozzle surface of the recording head (i.e., the face of the recording head in which the nozzles are disposed) to prevent ink within the nozzles from getting dried out and clogging the nozzles and dust and foreign substances from entering the nozzles, a wiper that wipes off the nozzle surface of the recording head to clean the nozzle surface, and so forth. After viscous ink is discharged from the nozzles into the cap that covers the nozzle surface, the wiper wipes off the nozzle surface to form a meniscus at the nozzles, thereby servicing the recording head.
There are known inkjet recording devices in which the recording head ejects ink droplets upward against the force of gravity from the nozzles to form an image on a downward facing side of a sheet. Such an inkjet recording device further includes an ink receiver that receives ink preliminary ejected from the nozzles to maintain stable ejection of ink droplets from the nozzles. The ink receiver has an opening through which the ink preliminary ejected from the nozzles enter the ink receiver. The ink receiver further has a leakage prevention unit provided above the opening so that the ink is prevented from leaking from the ink receiver via the opening.
However, when a nozzle surface of the recording head is capped with a cap member to discharge waste ink from the nozzles to the cap member, the cap member is filled with the waste ink thus discharged. Consequently, in the recording head that ejects the ink droplets vertically upward, the waste ink drops off from the recording head to inside the inkjet recording device when the cap member is removed from the nozzle surface of the recording head. Further, a larger amount of waste ink remains attached to the nozzle surface of the recording head after removal of the cap member from the nozzle surface, thereby increasing wiping and cleaning load.